Laser Shaving

ABSTRACT

A device configured to cut hair using laser light includes a handle portion and a shaving portion. The handle portion includes a battery and a laser light source. The laser light source is coupled to and configured to receive power from the battery. The laser light source is also configured to generate laser light having a wavelength selected to target a predetermined chromophore to effectively cut a hair shaft. The shaving portion includes a support and a single fiber optic supported by the support. The fiber optic has a proximal end, a distal end, an outer wall, and a cutting region positioned towards the distal end and extending along a portion of the side wall. The fiber optic is positioned to receive the laser light from the laser light source at the proximal end, conduct the laser light from the proximal end toward the distal end, and emit the light out of the cutting region and toward hair when the cutting region is brought in contact with the hair.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims the priority benefit of U.S. ProvisionalApplication No. 61/801,162, filed Mar. 15, 2013, the entirety of whichis hereby incorporated by reference herein.

BACKGROUND

1. Field

The present disclosure generally relates to devices and methods forcutting or processing matter using light, including but not limited toshaving using laser light.

2. Description of the Related Art

Shaving is most commonly performed using razors having one or more metalblades. However, razors can irritate and damage the user's skin. Razorsare also limited to removing hair at the surface of the skin, whichresults in the hair becoming visible again in a relatively short timeperiod. Various laser devices are also available for hair removal.However, laser hair removal devices and methods typically involve usinglaser light to destroy the hair follicle below the skin surface forpermanent or semi-permanent hair removal. Such devices and methods aretypically more dangerous, expensive, not suitable for home use, andoften do not provide effective cutting of lighter colored hair.

SUMMARY

The present disclosure describes devices and methods for cutting matter,including but not limited to shaving hair. In some embodiments, ashaving device uses electromagnetic radiation or light (e.g., laser orother light energy) to cut or damage one or more hair shafts. At leastone surface of at least one fiber or a light guide can emit lighttowards at least one hair shaft. In some embodiments, the fiber or lightguide is configured to couple light into at least one hair shaft throughat least one light transmitting surface of the fiber or light guide.Such devices can couple light into one or more hair shafts with orwithout a coupling enhancing medium, such as any such coupling mediumdescribed below, or others. Devices according to the present disclosureare effective, efficient, cost effective, and safe for home use.

In one embodiment, a device configured to cut hair using laser lightincludes a handle portion and a shaving portion. The handle portionincludes a battery and a laser light source. The laser light source iscoupled to and configured to receive power from the battery. The laserlight source is also configured to generate laser light having awavelength selected to target a predetermined chromophore to effectivelycut a hair shaft. The shaving portion includes a support and a singlefiber optic supported by the support. The fiber optic has a proximalend, a distal end, an outer wall, and a cutting region positionedtowards the distal end and extending along a portion of the side wall.The fiber optic is positioned to receive the laser light from the laserlight source at the proximal end, conduct the laser light from theproximal end toward the distal end, and emit the light out of thecutting region and toward hair when the cutting region is brought incontact with the hair.

The fiber optic may be further configured to prevent light from beingemitted from the cutting region when the cutting region is not incontact with the hair. The support may be T-shaped. The support mayinclude a channel configured to receive the fiber optic, and the fiberoptic may be positioned within the channel. In some embodiments, thewavelength is within one or more ranges selected from a group consistingof: 380 nm to 480 nm, 380 nm to 500 nm, 400 nm to 500 nm, 2500 nm to3500 nm, 2950 nm to 3050 nm, and 2700 nm to 3500 nm.

In some embodiments, the shaving portion is removably coupled to thehandle portion, the fiber optic is removably coupled to the support, orboth. The predetermined chromophore may be selected from the groupconsisting of: sebum, a fatty acid, phytoshingosine, ceramide,cholesterol, cholesterol sulfate, and cholesterol oleate. In someembodiments, the device also includes an optic configured to direct thelaser light from the laser light source to the proximal end of the fiberoptic.

In some embodiments, the fiber optic has a diameter in the range ofabout 4 microns to about 1000 microns. The device may also include areflector positioned at the distal end of the fiber optic and configuredto reflect light towards the fiber optic proximal end. The device mayalso include a vacuum source coupled to the support and configured toprovide aspiration near the cutting region.

In some embodiments, the fiber optic includes a core and a cladding thatsurrounds the core along the fiber optic length, except at the cuttingregion. The cutting region may have a radius of curvature that isdifferent than radius of curvature of the fiber optic near its proximalend. In some embodiments, a cross-sectional shape of the fiber optic atthe cutting region is wedge-shaped. In some embodiments, the fiber optictapers in diameter along the cutting region.

In yet another embodiment, a method of shaving hair with laser lightincludes providing a device configured to cut hair and directing laserlight from the device's light source, through its cutting region, andtowards a shaft of the hair to cut the hair. The device includes ahandle portion and a shaving portion. The handle portion includes abattery and a laser light source. The laser light source is coupled toand configured to receive power from the battery. The laser light sourceis also configured to generate laser light having a wavelength selectedto target a predetermined chromophore to effectively cut a hair shaft.

The shaving portion includes a support and a single fiber opticsupported by the support. The fiber optic has a proximal end, a distalend, an outer wall, and a cutting region positioned towards the distalend and extending along a portion of the side wall. The fiber optic ispositioned to receive the laser light from the laser light source at theproximal end, conduct the laser light from the proximal end toward thedistal end, and emit the light out of the cutting region and towards thehair when the cutting region is brought in contact with the hair.

The method may also include preventing light from being emitted from thecutting region when the cutting region is not in contact with the hair.The method may also include removably coupling: (1) the shaving portionto the handle portion, (2) the fiber optic to the support, or (3) both.The wavelength may be within one or more ranges selected from a groupconsisting of: 380 nm to 480 nm, 380 nm to 500 nm, 400 nm to 500 nm,2500 nm to 3500 nm, 2950 nm to 3050 nm, and 2700 nm to 3500 nm.

For purposes of summarizing the disclosure and the advantages achievedover the prior art, certain objects and advantages are described herein.Of course, it is to be understood that not necessarily all such objectsor advantages need to be achieved in accordance with any particularembodiment. Thus, for example, those skilled in the art will recognizethat the disclosure may be embodied or carried out in a manner thatachieves or optimizes one advantage or group of advantages as taught orsuggested herein without necessarily achieving other objects oradvantages as may be taught or suggested herein. All of theseembodiments are intended to be within the scope of the disclosureherein. These and other embodiments will become readily apparent tothose skilled in the art from the following detailed description havingreference to the attached figures, the disclosure not being limited toany particular disclosed embodiment(s).

BRIEF DESCRIPTION OF THE DRAWINGS

These and other features, aspects and advantages of the presentdisclosure will be described with reference to the following drawings,which are illustrative but should not be limiting of the presentdisclosure.

FIG. 1 illustrates an example embodiment of a laser shaving device;

FIG. 2 illustrates another example embodiment of a laser shaving device;

FIG. 3 illustrates another example embodiment of a laser shaving deviceresembling a straight razor;

FIG. 4 illustrates a fiber portion of a laser shaver coupling light intoa hair shaft; and

FIG. 5 illustrates a cross-sectional view of another embodiment of afiber at its cutting region.

DETAILED DESCRIPTION

Although certain embodiments and examples are described below, those ofskill in the art will appreciate that the disclosure extends beyond thespecifically disclosed embodiments and/or uses and obvious modificationsand equivalents thereof. Thus, it is intended that the scope of thedisclosure herein should not be limited by any particular embodimentsdescribed below.

Hair shafts can be severed with high intensity light via absorptionheating and burning and/or melting of the shaft. Some optical shavingdevices based on this mechanism have been envisioned as an alternativeto shaving with razors or laser hair removal. Some such devices includea plurality of optical fibers and are used to cut hair by coupling lightinto one end of the optical fibers and emitting the light out of theopposite end of the optical fibers and in a direction parallel to theirlongitudinal axes. One problem with using a plurality of optical fibersin this way is the increased loss of light into the cross-sectional areaof the claddings of the multiple fibers. Light energy is lost in thecladding of a fiber as light travels through it, and therefore, morefiber optics results in more light energy loss. In addition, whencoupling light from a single light source into a cross-sectional surface(e.g., the proximal end) of a plurality of fibers (e.g., a fiber-opticbundle), an additional problem is fraction losses into the spacesbetween the fibers, e.g. in the case of round fibers that are bundledtogether.

Devices and methods according to the present disclosure advantageouslyovercome these problems and disadvantages associated with claddingcross-sectional losses and/or fraction losses, resulting in a moreefficient device. The techniques described herein advantageously allowthe devices to be smaller, lighter, and/or less costly to manufacture.In addition, in some embodiments, a single light source is coupled intoa single fiber-optic conduit. The single fiber-optic conduit isconfigured to emit light out of a predetermined area along the side ofthe fiber's outer wall, as discussed in greater detail below. The sideof the fiber's outer wall may be conditioned or configured in a mannerthat light can only escape out of the side of the fiber's outer wallsurface when the outer wall surface is brought into contact with hair.In such cases, intense, energy-focused light is emitted only at suchcontact locations. This side-firing, focusing effect advantageouslyresults in being able to effectively cut hair (and more generally, toremove matter) using less energy. Therefore, in some embodiments, anefficient shaving device may include a battery powered, hand-helddevice. In addition, because light is only emitted out of the side ofthe fiber when in contact with hair (or other targeted matter), thedevice is safer than devices that continuously emit light out of theirdistal ends when activated. In addition, the light exiting a side-firingfiber-optic shaving device exits the fiber-optic at a larger divergenceangle than an end-firing fiber-optic. Therefore, because of such largerdivergence angle, the side-firing fiber-optic shaving device is saferthan end-firing devices, as the light from a side-firing device willdiverge quicker and become weaker in intensity and fluence (power andenergy per area) over distance.

Additionally, to damage and/or cut one or more hair shafts with light,at least some of the light energy is absorbed by the hair shaft andconverted into heat or induce a bond breaking mechanism. There are threechromophores in hair that substantially absorb light—melanin, keratin,and water. Keratin and water have absorption peaks at around 3000 nm.Melanin has an absorption peak around 300 nm, but remains relativelyflat, decreasing almost linearly (on a logarithmic scale) to about 3000nm. Darker hair, for example, black and brown hair, contains melanin andcan be damaged or cut by sufficient amounts of ultraviolet (UV), visible(VIS), near infrared (NIR), and many infrared (IR) wavelengths. Previousconceptual models, devices, and methods have typically used laser diodesemitting light having a wavelength of about 810 nm to cut or damage thehair. Light having a wavelength about 600 nm is advantageously notabsorbed by blood or not absorbed by blood to a large extent, whichhelps reduce the risk of adverse effects to the patient, as light havinga wavelength above about 600 nm is not absorbed by hemoglobin. Someprevious devices and methods have attempted to use flash lamps as alight source; however, these have often been impractical for couplingthe light into a delivery system.

However, lighter hair, for example, white and blonde hair, has little orno melanin; therefore, previous devices and techniques attempted to cutlight hair by targeting water or keratin. Hair normally contains about12% water. In some cases, when there is no melanin or an insufficientamount of melanin, NIR and/or IR light can be used and absorbed by waterto attempt to cut or damage hair. However, when targeting water, if thefluence of the light is not initially sufficient, the water evaporatesfrom the hair shaft and therefore cannot be used in a second attempt tocut or damage the hair shaft. Surprisingly, white light with or withoutUV light can damage or cut light, for example, white or blonde, hair.

In some embodiments, devices and methods of the present disclosure useone or more of purple (about 400 nm or in the range of about 380 nm toabout 480 nm), blue, and/or blue-green light having wavelengths in therange of about 380 nm to about 500 nm or about 400 nm to about 500 nm todamage or cut hair. In some embodiments, light having a wavelength ofabout 3000 nm is used to damage or cut hair. Surprisingly, light inthese ranges is capable of damaging or cutting light hair, for example,even white and blonde hair. These wavelengths can be selected to targetpreviously unknown chromophores, for example, sebum from the hairfollicle. In some embodiments, the wavelengths are selected to targetone or more fatty acid(s), phytoshingosine, ceramide, cholesterol,cholesterol sulfate, and/or cholesterol oleate. In some embodiments, thelight is selected to target a fatty layer of the hair, on an outersurface of the hair, in the hair, and/or between keratin flakes of thehair. In some embodiments, a user can apply an extrogen chromophore tothe hair, the shaving device, or both prior to shaving with any of thedevices or according to any of the methods described herein. Theextrogen chromophore can be selected to target any desiredwavelength(s). These chromophores can advantageously exhibit greaterabsorption at these wavelengths that previously known chromophores.Additionally, hair typically contains air between layers of keratin. Theair pockets can scatter light directed at the hair and increasinglyscatter the light as wavelength decreases. Increased scatteringlengthens the path of the light in the hair shaft, which increases theprobability of the light being absorbed by the hair shaft. The shorterwavelengths in the blue and blue-green range can therefore also causemore scattering, which increases the path length and probability ofabsorption.

In some embodiments, a shaving device according to the presentdisclosure can include a single side firing waveguide, such as a laserfiber optic, housed in or supported by a mechanical support. In otherembodiments, the shaving device includes more than one fiber.Additionally, in some embodiments, light can be emitted from an end ofthe waveguide or fiber instead of or in addition to a side.

An example embodiment of a laser shaver 100 is shown in FIG. 1. Theshaver 100 includes a handle 102 and a support 140 that supports anoptical waveguide, for example, an optical fiber 104, coupled to andextending from the handle 102. The waveguide can be a fiber, a hollowlight guide, a liquid light guide, or any other light guide. The handle102 generally includes a power source 108, at least one light source110, for example, a diode laser along with any laser driver boardsneeded, and one or more optics 112. In some embodiments, the lightsource can be or include a Xenon flash lamp. The light source can beconfigured to emit various wavelengths of light, for example, betweenabout 2500 nm to about 3500 nm, for example, about 3000 nm, or betweenabout 400 nm to about 500 nm. In some embodiments, the light source canbe configured to emit UVA light, UVB light, light that is at least about20% UVA, light that is at least about 20% in the 400 nm to 500 nm range,light that is at least about 20% in the 2700 nm-3500 nm range, lightthat is at least about 20% in the 3000 nm range, light that includes UVAlight, light that includes light in the range of 380 nm to 480 nm range,light that includes light in the 400 nm to 500 nm range, light thatincludes light in the 2700 nm to 3500 nm range, light that issubstantially in the 400 nm to 500 nm range, light that is substantiallyin the 2700 nm to 3500 nm range, and/or light that is substantiallyabout 3000 nm or about 3000 nm±500 nm in wavelength. In someembodiments, light sources of different wavelengths can be used with asingle fiber 104. In some embodiments, light sources of differentwavelengths can be coupled into multiple fibers or other light guides.

The power source 108 is electrically coupled to the light source 110 topower the light source 110. In use, the light source 110 emits light,which is directed to the one or more optics 112. The one or more optics112 are configured to couple the light from the light source 110 intothe proximal end 104 a of the fiber 104. The one or more optics 112 canbe a lens or lens system or one or more reflectors. In some embodiments,a separate optic is not necessary, and light can be coupled into thewaveguide by proximity or direct or indirect contact. In any embodimentaccording to the present disclosure, the light can be laser light,coherent light, and/or at least one part of non-collimated light. Partor all of the shaver 100 can be waterproof or water resistant. In someembodiments, the light source 110 can be located outside the handle 102,for example in a base unit. The base unit can be electrically and/oroptically connected to the handle 102 by an electrical conductor or alight conductor. For example, a fiber or umbilicus can transfer thelight from the base unit to the handle 102.

FIG. 4 illustrates a partial view of the fiber 104. The fiber 104 canhave various cross-sectional shapes, for example, round as shown in theillustrated embodiment. As shown, the fiber 104 includes a core 114 andan outer cladding 116 surrounding the core 114. In some embodiments, thefiber core 114 has a diameter in the range of about 4 microns to about1000 microns. In some embodiments, the fiber core 114 has a diameterbetween 0.5 mm and 2 mm. In use, light rays 118 propagate along thefiber 104 from the proximal end 104 a toward the distal end 104 b. Thelight rays 118 are confined within the core 114 due to the core's higherindex of refraction compared to the lower index of refraction of thecladding 116. The fiber 104 includes an aperture or a cutting orlight-emitting surface 106 at or near the distal end 104 b of the fiber104. The cutting surface 106 can be shaped to a line having a length ofbetween about 2 mm and about 200 mm. In some embodiments, the cuttingsurface 106 includes a plurality of optical waveguides or fibers. Forexample, a single fiber 104 coupled to the handle 102 can couple to aplurality of fibers. In other embodiments, a plurality of fibers orother waveguides can extend from the handle 102. In some embodiments,the cutting surface 106 is positioned along the length of the fiberoptic 104, and spaced from the fiber optic's distal end 104 b. Forexample, the entire cutting surface 106 can be spaced a distance fromthe fiber optic's distal end 104b. The fiber optic 104 may be configuredsuch that the cutting surface 106 does not extend to the fiber's distalend 104 b.

FIG. 5 illustrates a cross-sectional view of another embodiment of afiber 104 at its cutting region. The fiber 104 includes a core 114 andan outer cladding 116 that partially surrounds the core 114. The outersurface 130 of the core 114 includes a contoured portion 132. In theillustrated embodiment, the contoured portion 132 is concave, althoughin other embodiments, the contoured portion 132 can be convex, planar,pointed, wedge-shaped, etc. The fiber 104 and the cutting region can beformed by drawing, extruding, casting, or equivalent technique. Thecurvature of the contoured portion 132 can provide a lensing effect toassist in directing light out of the side of the fiber 104 and into thehair shaft 134 by forming an optical focusing region 136 within the hairshaft 134. The contoured portion 132 may be shaped to conform to thehair's outside radius and focus energy inside the hair shaft 134 whilebending the hair shaft 134. In some embodiments, the contoured portion132 is covered at least partially with a coating. For example, a portionof the cladding 116 may be removed from at least a portion of the fiber104 to expose a portion of the core 114, e.g., on a side of the fiberalong its length, and the exposed portion may subsequently be covered bya coating. The coating may be referred to as a “re-cladding.” Thecoating may include any of the coating described above, including butnot limited to a clear resin, an organic grease, silicone, petroleumgel, clear PTFE, clear ePTFE, clear rubber, clear RTV, etc. In someembodiments, the coating may be reflective, transmitting,non-reflective, lubricous, and/or configured to grab onto hair.

In some embodiments, the fiber 104 can include a mirror or fiberre-circulator (not shown) at or near a distal end 104 b to reflect thelight traveling within the fiber 104 to increase light output andefficiency. The mirror can return and help direct at least part of anynon-consumed light to the cutting surface 106. In some embodiments, oneor more optical reflective coatings are applied to at least part of thefiber 104 to help recycle radiation within the fiber 104 and improveefficiency.

In some embodiments, the shaver 100 also includes a vacuum (not shown),with an optional filter, positioned near or alongside the fiber 104. Thevacuum can be configured to remove smoke that may result from burningthe hair.

The shaver 100 can have various configurations, for example as shown inFIGS. 1-3. The embodiments of FIGS. 1 and 2 have substantially the samehandle 102 configuration. However, the fibers 104 and/or supports 140 ofthe embodiments of FIGS. 1 and 2 have different shapes orconfigurations. The fiber 104 and/or support 140 can have various shapesand configurations to improve ease of use of the shaver 100. Forexample, the fiber 104 and/or support 140 can be substantially linear,curved, or include both linear and curved segments. The fiber 104 and/orsupport 140 can be L shaped, S shaped, T-shaped, or any other suitableshape. In some embodiments, the fiber 104 is held or at least partiallycontained by a mechanical support 140. Such a mechanical support 140provides greater strength and structure to the shaver 100 as a singlefiber 104 alone could be too flexible to maintain a desired shape andcould be more vulnerable to damage. In some embodiments, the shaver 100can be configured to resemble a traditional bladed razor. In theembodiment of FIG. 3, the shaver 100 is similar to a straight razor. Inthe illustrated embodiment, the shaver 100 includes a support segment120 that resembles the blade of a straight razor. The support segment120 is coupled to the handle 102 via a hinge or pivot 122. In someembodiments, the support segment 120 is pivotally coupled to the handle102 so that the shaver 100 is foldable. The cutting surface 106 of thefiber 104 can be positioned along an edge of the support segment 120 sothat the user can use the shaver 100 in a similar manner as he or shewould use a straight razor. In other embodiments, the shaver 100 canresemble a safety razor, and the cutting surface 106 can be positionedwhere a blade would be in a traditional safety razor.

In some embodiments, the shaver 100 is disposable. In other embodiments,the handle 102 is reusable, and the fiber 104 portion including themechanical support 140 are disposable, similar to a safety razor havingdisposable cartridges. The fiber 104 portion can be removeably coupledto the handle 102 and can be replaced after a number of uses. Theproximal end 104 a of the fiber 104 can include a connector configuredto couple to a connector on the handle 102. One or both of theconnectors can be waterproof or water resistant. In some embodiments, anintermediate waveguide can couple a disposable fiber 104 portion to thehandle 102.

In some embodiments, the cutting surface 106 includes a portion of thefiber 104 where the cladding 116 has been removed, for example as shownin FIG. 4. The cladding 116 can be removed via various methods, forexample, chemical and/or mechanical methods. Because air has a lowerindex of refraction than the core 114, the light rays 118 are stillconfined within the fiber 104. The cutting surface 106 of the shaver 100must therefore be in contact with hair 10, which has a higher index ofrefraction than the core 114, for light to be able to couple out of thefiber 104. For example, a fiber 104 having a silica core can have anindex of refraction of about 1.47, whereas hair, which is made mostly ofkeratin with lipids, typically has an index of refraction of about 1.56.In other words, little to no light leaks out of or is emitted from thefiber 104 when the cutting surface 106 is not in contact with the hairor another object having a higher index of refraction than the core.This advantageously confines the laser radiation for safety reasons, forexample, for eye safety, and improves the efficiency of the device asthe light emitted is used for cutting hair rather than losing light tothe room. When the cutting surface 106 is placed into contact with hair10, the hair shaft begins to draw the radiation from the fiber 104, forexample, via evanescent transfer of radiation from the fiber 104 to thehair shaft 10. In some embodiments, the cladding 116 is only removedfrom a portion of the circumference of the fiber 104 as shown in FIG. 4.This advantageously reduces the risk of a user accidentally contactinganother portion of the body with a light emitting portion of the fiber104. In some embodiments, the shaver 100 can include a sensor configuredto detect contact with hair and the shaver 100 can be configured suchthat the light source 110 is only turned on or active when the cuttingsurface 106 is determined to be in contact with hair.

In some embodiments, light is coupled out of the fiber 104 at thecutting surface 106 by using a coating or coupling material, instead ofor in addition to removal of the cladding 116. In some such embodiments,the cutting surface 106 does not have to be in contact with hair to emitlight. For example, the cutting surface 106 can be processed withphotolithography or etching to create a surface that allows light toexit the fiber 104. In some embodiments, a scatting material can becoupled, e.g., glued or adhered, to the cutting surface 106. In someembodiments, both the cladding 116 is removed from the cutting surface106 and the cutting surface 106 is further processed or a scatteringmaterial is coupled to the cutting surface 106. In some embodiments, oneor more coatings are applied to at least part of the fiber 104 toenhance energy transfer to the hair shaft. Such coating may optionallybe applied to the hair as well (or instead of applying such materials tothe fiber 104). Any of a variety of coating or coupling materials may beused, including but not limited to, any of the chromophores discussedherein, petroleum gel, a resin, silicone, room-temperature vulcanizationsilicone (RTV), polytetrafluoroethylene (PTFE), expandedpolytetrafluoroethylene (ePTFE), etc. In some embodiments, the fiber 104or cutting surface 106 is shaped to optimize radiation transfer to thehair. For example, a distal portion of the fiber 104 can be tapered tochange the angles of light being propagated within the fiber until atleast some of the light couples out of the fiber 104.

In some embodiments, the shaver 100 includes at least one light frontcross-section shaping optic that at least partially arranges coherentlight along a line of between about 2 mm and about 200 mm. In some suchembodiments, the light passes directly from the light shaping optic tothe hair. In other embodiments, the light passes through at least onemore optic to be directed to the hair. In some embodiments, the lightshaping optic is a waveguide or fiber that at least partially changesthe shape of light emitted to a line having a length of between about 2mm and about 200 mm. In some embodiments, light from the light source iscoupled into at least one blade shaped optic that guides at least partof the light to the hair. The blade shaped optic can be a light guideand/or a light transmitter. The blade shaped optic can be detachable,consumable, and/or exchangeable.

For eye safety and/or skin comfort and/or safety, the light ispreferably not emitted directly toward the hair, face, or other bodyparts. In some embodiments, the shaving device is configured to directthe light emitted in a direction parallel or substantially parallel tothe skin surface or at an angle selected such that the light does notsubstantially enter the skin and/or eyes. For example, the shaver 100and cutting surface 106 can be configured such that light incident onthe hair is aimed toward the hair at an angle in the range of about±45°, for example, in the range of about ±5°, ±10°, or ±25°, to thesurface of the skin. In some embodiments, the shaver 100 includes atleast one sensor configured to detect a broken fiber. For example, asensor can be positioned at or near the distal end 104 b of the fiber104 and can detect the amount of light incident on the sensor. If littleor no light is reaching the sensor at the distal end 104 b, the fiber104 may be broken and allowing radiation to leak out, which can create asafety hazard. Therefore, if the sensor detects little or no lightreaching the distal end 104 b, the shaver 100 can turn off the light orpower source.

When cutting white (or light) hair with blue light, e.g., at about 403nm, approximately twice the fluence (or energy level) is needed comparedto cutting brown hair (for example, by targeting melanin). Increasingthe power can therefore improve the efficacy of the devices and methodsdescribed herein in some cases; however, increasing the power can alsoincrease the risk of adverse effects in some cases. In some embodiments,a shaving device as described herein includes one ore more sensorsconfigured to detect or gather data indicative of the chromophore(s)present in the target hair. For example, upon contact with the hair, thedevice can emit light into the hair, and a sensor can detect the lightreflected to allow the device to determine the wavelengths of lightabsorbed. In some embodiments, the sensor could be located in the handleof the device. In some embodiments, the sensor can be a MEMS device thatfunctions as a spectrometer and is located on the portion of the deviceconfigured to emit light to and/or contact the hair. If the sensordetects and/or the device determines based on sensor data that the haircontains a sufficient amount of melanin, the device can reduce theenergy level or power and/or adjust the wavelength of light emitted totarget a predetermined chromophore (e.g., melanin). If the sensordetects and/or the device determines based on sensor data that the hairlacks sufficient melanin but contains sufficient sebum, the device canincrease the energy level or power and/or adjust the wavelength emittedto target the sebum.

More than one device as described herein can be used synchronously or insequence to cut or damage hair.

Although the devices and methods herein have been described with respectto cutting or damaging hair, these devices and methods can be used forother applications, for example, surgery. The device or cutting surface106 can be shaped similar to a knife, surgical scalpel, or other cuttingtool. In some embodiments, when using the device to cut tissue, thedevice can also act as a coagulating and bleeding stopping means bymeans of the heat created by light absorbed into the tissue. The lightcan be modulated and tuned to cut tissue or coagulate.

It should be emphasized that many variations and modifications may bemade to the embodiments described herein, the elements of which are tobe understood as being among other acceptable examples. All suchmodifications and variations are intended to be included herein withinthe scope of this disclosure and protected by the following claims.Further, nothing in the foregoing disclosure is intended to imply thatany particular component, characteristic or process step is necessary oressential.

1. A device configured to cut hair using laser light, the device comprising: a handle portion, the handle portion comprising: a battery; and a laser light source coupled to and configured to receive power from the battery, the laser light source further configured to generate laser light having a wavelength selected to target a predetermined chromophore to effectively cut a hair shaft; and a shaving portion, the shaving portion comprising: a support, and a single fiber optic supported by the support, the fiber optic having a proximal end, a distal end, an outer wall, and a cutting region positioned towards the distal end and extending along a portion of the side wall, wherein the fiber optic is positioned to receive the laser light from the laser light source at the proximal end, conduct the laser light from the proximal end toward the distal end, and emit the light out of the cutting region and toward hair when the cutting region is brought in contact with the hair.
 2. The device of claim 1, wherein the fiber optic is further configured to prevent light from being emitted from the cutting region when the cutting region is not in contact with the hair.
 3. The device of claim 1, wherein the support is T-shaped.
 4. The device of claim 1, wherein the support comprises a channel configured to receive the fiber optic, and wherein the fiber optic is positioned within the channel.
 5. The device of claim 1, wherein the wavelength is within one or more ranges selected from a group consisting of: 380 nm to 480 nm, 380 nm to 500 nm, 400 nm to 500 nm, 2500 nm to 3500 nm, 2950 nm to 3050 nm, and 2700 nm to 3500 nm.
 6. The device of claim 1, wherein the shaving portion is removably coupled to the handle portion.
 7. The device of claim 1, wherein the fiber optic is removably coupled to the support.
 8. The device of claim 1, wherein the predetermined chromophore is selected from the group consisting of: sebum, a fatty acid, phytoshingosine, ceramide, cholesterol, cholesterol sulfate, and cholesterol oleate.
 9. The device of claim 1, further comprising an optic, the optic configured to direct the laser light from the laser light source to the proximal end of the fiber optic.
 10. The device of claim 1, wherein the fiber optic has a diameter in the range of about 4 microns to about 1000 microns.
 11. The device of claim 1, further comprising a reflector positioned at the distal end of the fiber optic and configured to reflect light towards the fiber optic proximal end.
 12. The device of claim 1, further comprising a vacuum source coupled to the support and configured to provide aspiration near the cutting region.
 13. The device of claim 1, wherein the fiber optic comprises a core and a cladding that surrounds the core along the fiber optic length, except at the cutting region.
 14. The device of claim 1, wherein the cutting region has a radius of curvature that is different than radius of curvature of the fiber optic near its proximal end.
 15. The device of claim 1, wherein a cross-sectional shape of the fiber optic at the cutting region is wedge-shaped.
 16. The device of claim 1, wherein the fiber optic tapers in diameter along the cutting region.
 17. A method of shaving hair with laser light, the method comprising: providing a device configured to cut hair, the device comprising: a handle portion, the handle portion comprising: a battery; and a laser light source coupled to and configured to receive power from the battery, the laser light source further configured to generate laser light having a wavelength selected to target a predetermined chromophore to effectively cut a hair shaft; and a shaving portion, the shaving portion comprising: a support, and a single fiber optic supported by the support, the fiber optic having a proximal end, a distal end, an outer wall, and a cutting region positioned towards the distal end and extending along a portion of the side wall, wherein the fiber optic is positioned to receive the laser light from the laser light source at the proximal end, conduct the laser light from the proximal end toward the distal end, and emit the light out of the cutting region and towards the hair when the cutting region is brought in contact with the hair; and directing the laser light from the laser light source, through the cutting region, and towards a shaft of the hair to cut the hair.
 18. The method of claim 17, further comprising preventing light from being emitted from the cutting region when the cutting region is not in contact with the hair.
 19. The method of claim 17, further comprising removably coupling: (1) the shaving portion to the handle portion, (2) the fiber optic to the support, or (3) both.
 20. The method of claim 17, wherein the wavelength is within one or more ranges selected from a group consisting of: 380 nm to 480 nm, 380 nm to 500 nm, 400 nm to 500 nm, 2500 nm to 3500 nm, 2950 nm to 3050 nm, and 2700 nm to 3500 nm. 